Zobrazeno 1 - 10
of 271
pro vyhledávání: '"Nils Andersson"'
Publikováno v:
Entropy, Vol 26, Iss 8, p 621 (2024)
We develop an action principle for producing a single-fluid two-constituent system with dissipation in general relativity. The two constituents in the model are particles and entropy. The particle flux creation rate is taken to be zero, while the ent
Externí odkaz:
https://doaj.org/article/11f0076b1bbd45959d4404f34f8918be
Publikováno v:
Universe, Vol 9, Iss 6, p 282 (2023)
We develop an action principle to construct the field equations for dissipative/resistive general relativistic two-temperature plasmas, including a neutrally charged component. The total action is a combination of four pieces: an action for a multifl
Externí odkaz:
https://doaj.org/article/e82e9e1aefbd42f9ba145a0313ae71ba
Publikováno v:
Universe, Vol 9, Iss 5, p 226 (2023)
We revisit the calculation of mode oscillations in the ocean of a rotating neutron star, which may be excited during thermonuclear X-ray bursts. Our present theoretical understanding of ocean modes relies heavily on the traditional approximation comm
Externí odkaz:
https://doaj.org/article/0737544eca4140939fad3e6fab54fddc
Autor:
Nils Andersson, Fabian Gittins
Publikováno v:
The Astrophysical Journal, Vol 945, Iss 2, p 139 (2023)
We revisit the problem of inertial r-modes in stratified stars, drawing on a more precise description of the composition stratification in a mature neutron star. The results highlight issues with the traditional approach to the problem, leading us to
Externí odkaz:
https://doaj.org/article/a64311481f8147bf87f808e583220125
Autor:
Nils Andersson, Andreas Schmitt
Publikováno v:
Particles, Vol 2, Iss 4, Pp 457-480 (2019)
Two coupled, interpenetrating fluids suffer instabilities beyond certain critical counterflows. For ideal fluids, an energetic instability occurs at the point where a sound mode inverts its direction due to the counterflow, while dynamical instabilit
Externí odkaz:
https://doaj.org/article/ae1cec5fe2d447e5b6bb28a467074ad2
Autor:
Nils Andersson
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 8 (2021)
This brief review introduces the notion of a relativistic multifluid system—a multi-component system with identifiable relative flows—and outlines a set of models for scenarios relevant for different astronomical observation channels. The specifi
Externí odkaz:
https://doaj.org/article/054925bfbbc240c3abd4f131992fdd03
Publikováno v:
Universe, Vol 7, Iss 4, p 111 (2021)
The I-Love-Q relations are approximate equation-of-state independent relations that connect the moment of inertia, the spin-induced quadrupole moment, and the tidal deformability of neutron stars. In this paper, we study the I-Love-Q relations for su
Externí odkaz:
https://doaj.org/article/62fa646bc5d14918aa19df10857d811e
Autor:
Nils Andersson
Publikováno v:
Universe, Vol 7, Iss 4, p 97 (2021)
We provide a bird’s-eye view of neutron-star seismology, which aims to probe the extreme physics associated with these objects, in the context of gravitational-wave astronomy. Focussing on the fundamental mode of oscillation, which is an efficient
Externí odkaz:
https://doaj.org/article/091f28832a1649dd9247496d8b5f2562
Autor:
Nils Andersson
Publikováno v:
Universe, Vol 7, Iss 1, p 17 (2021)
As mature neutron stars are cold (on the relevant temperature scale), one has to carefully consider the state of matter in their interior. The outer kilometre or so is expected to freeze to form an elastic crust of increasingly neutron-rich nuclei, c
Externí odkaz:
https://doaj.org/article/b0f7247a00204fc18b38b3126f936e9a
Publikováno v:
Journal of Combustion, Vol 2016 (2016)
The current study presents a method to model the flameless oxy-fuel system, with a comparative approach, as well as validation of the predictions. The validation has been done by comparing the predicted results with previously published experimental
Externí odkaz:
https://doaj.org/article/0ef45fcaf01c4b8c9d372aeeb8fca766